K. Kawahata
A5103033541- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Laser Design and Applications
- Gyrotron and Vacuum Electronics Research
- Parkinson's Disease Mechanisms and Treatments
- Peroxisome Proliferator-Activated Receptors
- Laser-induced spectroscopy and plasma
- Spectroscopy and Laser Applications
- Atomic and Subatomic Physics Research
- Physics of Superconductivity and Magnetism
- Optical Systems and Laser Technology
- Advanced Measurement and Metrology Techniques
- Magneto-Optical Properties and Applications
- Nuclear Physics and Applications
- Dust and Plasma Wave Phenomena
- Alzheimer's disease research and treatments
- Electrostatic Discharge in Electronics
- Photonic and Optical Devices
- Receptor Mechanisms and Signaling
Tohoku University
2016-2025
Pharmac
2010-2023
National Institute for Fusion Science
2008-2017
National Institutes of Natural Sciences
2001-2017
Tohoku Medical and Pharmaceutical University
2017
Tokyo Institute of Technology
2009-2015
The Graduate University for Advanced Studies, SOKENDAI
2000-2013
Miyagi University
2013
Nagoya University Hospital
2013
The University of Tokyo
2012
The Large Helical Device (LHD) has successfully started running plasma confinement experiments after a long construction period of eight years. During the and machine commissioning phases, variety milestones were attained in fusion engineering which led to first operation, was ignited on 31 March 1998. Two experimental campaigns carried out In campaign, magnetic flux mapping clearly demonstrated nested structure surfaces. conducted with second harmonic 84 82.6 GHz ECH at heating power input...
The Large Helical Device (LHD) is a heliotron-type device employing large-scale superconducting magnets to enable advanced studies of net-current-free plasmas. major goal the LHD experiment demonstrate high performance helical plasmas in reactor-relevant plasma regime. Engineering achievements and operational experience greatly contribute technological basis for fusion energy reactor. Thorough exploration scientific systematic understanding physics an important step In 12 years since initial...
As the finalization of a hydrogen experiment towards deuterium phase, exploration best performance plasma was intensively performed in large helical device. High ion and electron temperatures, Ti Te, more than 6 keV were simultaneously achieved by superimposing high-power cyclotron resonance heating onneutral beam injection (NBI) heated plasma. Although flattening temperature profile core region observed during discharges, one could avoid degradation increasing density. Another key parameter...
Understanding the intricate role of dopamine D1–D5 receptors is pivotal in addressing challenges posed by aging global population, as well social stress and advancing therapeutic interventions. Central to diverse brain functions such movement, cognition, motivation, reward, are ubiquitously distributed across various nuclei. This comprehensive review explores nuanced each receptor, D1, D2, D3, D4, D5, distinct regions, elucidating alterations witnessed several neurological psychiatric...
The Large Helical Device (LHD) experiments [O. Motojima, et al., Proceedings, 16th Conference on Fusion Energy, Montreal, 1996 (International Atomic Energy Agency, Vienna, 1997), Vol. 3, p. 437] have started this year after a successful eight-year construction and test period of the fully superconducting facility. LHD investigates variety physics issues large scale heliotron plasmas (R=3.9 m, a=0.6 m), which stimulates efforts to explore currentless disruption-free steady under an optimized...
Divertor plasma characteristics in the Large Helical Device (LHD) have been investigated mainly by using Langmuir probes. The three-dimensional structure of helical divertor, which is naturally produced heliotron-type magnetic configuration, clearly seen measured particle and power deposition profiles on divertor plates. These observations are consistent with numerical results field line tracing. flux to plates increases almost linearly averaged density. high-recycling regime detachment,...
A collective Thomson scattering (CTS) diagnostic was developed and used to measure the bulk fast ions originating from 180 keV neutral beams in Large Helical Device (LHD). Electromagnetic waves a gyrotron at 77 GHz with 1 MW power output function as both probe electron cyclotron heating beam. To clarify applicability of frequency band, we investigated dependence receiver beam trajectories plasmas high densities (4–5) × 1019 m−3 low (1–2) m−3. At density, stray radiation component observed...
We report observations of the dynamic response micro-fluctuations and turbulent flux to a low-frequency heating power modulation in Large Helical Device. The responses heat micro-fluctuation intensity differ from that change temperature gradient. This result violates local transport model, where turbulence is determined by A new relationship between flux, gradient found. In addition gradient, rate proposed as new, direct controlling parameter explain fast against periodic power.
Multiple sclerosis (MS) is an autoimmune disease characterised by the demyelination of mature oligodendrocytes in central nervous system. Recently, several studies have indicated vital roles fatty acid-binding proteins (FABPs) 5 and 7 regulating immune response.We assessed a novel FABP5/FABP7 inhibitor, FABP ligand 6 (MF 6), as potential therapeutic for MS therapy. In vivo, we established MOG35-55-administered experimental encephalomyelitis (EAE) mice mouse model, followed prophylactic...
Radial profiles of ion temperature and plasma flow are measured at the n/m = 1/1 magnetic island produced by external perturbation coils in Large Helical Device. The sheared poloidal flows radial electric field observed boundaries island, because vanishes inside static island. When width becomes large, along flux surface appears around O point direction which reduces shear boundary
In the first four years of LHD experiment, several encouraging results have emerged, most significant which is that MHD stability and good transport are compatible in inward shifted axis configuration. The observed energy confinement at this optimal configuration consistent with ISS95 scaling an enhancement factor 1.5. over smaller heliotron devices attributed to high edge temperature. We find plasma average beta 3% stable configuration, even though theoretical conditions Mercier modes...
Recent experimental results in the Large Helical Device have indicated that a large pressure gradient can be formed beyond stability criterion for Mercier (high-n) mode. While against an interchange mode is violated inward-shifted configuration due to enhancement of magnetic hill, neoclassical transport and confinement high-energy particle are, contrast, improved by this inward shift. Mitigation unfavourable effects MHD instability has led significant extension operational regime....
In the Large Helical Device (LHD), highest operational averaged beta value has been expanded from 3.2% to 4% in last 2 years by increasing heating capability and exploring a new magnetic configuration with high aspect ratio. Although magneto-hydrodynamic (MHD) stability properties are considered be unfavourable configuration, efficiency due neutral beams transport expected favourable high-beta range. order clarify effect of global ideal MHD unstable mode on regimes helical systems,...
The actin capping protein (CP) tightly binds to the barbed end of filaments, thus playing a key role in actin-based lamellipodial dynamics. V-1 and CARMIL proteins directly bind CP inhibit filament activity CP. completely inhibits from interacting with end, whereas act on end-bound facilitate its dissociation (called uncapping activity). Previous studies have revealed striking functional differences between two regulators. However, molecular mechanisms describing how these remains poorly...
Since the successful first plasma generation in middle of 2008, three experimental campaigns were successfully made for KSTAR device, accompanied with a necessary upgrade power supply, heating, wall-conditioning and diagnostic systems. was operated toroidal magnetic field up to 3.6 T circular shaped plasmas current 700 kA pulse length 7 s, have been achieved limited capacity PF magnet supplies. The mission program is achieve steady-state operations high performance relevant ITER future...
Metallic mirrors will be used as plasma-viewing elements in all optical and laser diagnostic systems ITER. In the harsh environment of ITER, performance decrease mainly because erosion their surfaces deposition impurities. The deterioration properties directly affect entire respective ITER diagnostics, possibly leading to shutdown. Therefore, R&D on is crucial importance for diagnostics. There a coordinated worldwide programme supervised by Specialists Working Group first International...
This Letter presents the discovery of macroscale electron temperature fluctuations with a long radial correlation length comparable to plasma minor radius in toroidal plasma. Their spatiotemporal structure is characterized by low frequency $\ensuremath{\sim}1--3\text{ }\text{ }\mathrm{kHz}$, ballistic propagation, poloidal or mode number $m/n=1/1$ (or $2/1$), and an amplitude $\ensuremath{\sim}2%$ at maximum. Nonlinear coupling between long-range microscopic identified. A change fluctuation...
α-Synuclein is an abundant neuronal protein that accumulates in insoluble inclusions Parkinson′s disease and other synucleinopathies. Fatty acids partially regulate accumulation, mesencephalic dopaminergic neurons highly express fatty acid-binding 3 (FABP3). We previously demonstrated FABP3 knockout mice show decreased oligomerization degeneration of tyrosine hydroxylase (TH)-positive vivo. In this study, we newly investigated the importance uptake, 1-methyl-4-phenylpyridinium (MPP+)-induced...
Early identification of the poor prognosis subtype by surrogate markers would be advantageous for selecting treatments Parkinson's disease (PD). The aim present study was to test whether plasma neurofilament light chain (NF-L), total tau (t-tau), ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), fatty acid-binding protein 3 (FABP3), and phosphorylated (p-tau) can used as prognostic biomarkers in PD. In study, both retrospective prospective studies were performed. Plasma samples at baseline...
A multichannel far-infrared laser interferometer system has been developed for the measurement of spatial and temporal behaviors electron density on Large Helical Device (LHD) at National Institute Fusion Science. Of several candidates high power sources a 119 μm CH3OH was taken as probing light. The optical configuration is Michelson type with 13 channels. mounted massive stainless frame floated three vibration isolating mounts. resolution fringe counters 1/100 fringes, it corresponds to...
Evidence for a reduction of heat transport inside the magnetic island O point is observed from propagation cold pulse produced by tracer encapsulated solid pellet in Large Helical Device. A small peak and slow are island. significant result that electron diffusivity estimated to be 0.2 m(2)/s which smaller than outside an order magnitude.